FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Automatic Temperature Control (ATC) System





AUTOMATIC TEMPERATURE CONTROL (ATC)

Each of the A/C heater controls in the front switchbank are resistor type controls. When a button is pushed, or a knob is turned, the switchbank sends a resistive signal over hard-wired circuits to the U-Connect Touch (TM) screen module. The controls in the U-Connect Touch (TM) screen module mimic the action selected on the switchbank. The U-Connect Touch (TM) screen module communicates the heater and A/C control request signals to the A/C heater module.

The A/C heater module is a dedicated microprocessor that automatically drives the electrically operated air-door actuators for the Dual Zone Automatic Temperature Control (ATC) heating and A/C systems. The ATC A/C heater module obtains sun load, in-car temperature and evaporator temperature information through hard-wired circuits, and occupant heating and A/C settings and other required vehicle information over the Controller Area Network (CAN) data bus A/C And Heater Control Module - Operation.

The Dual Zone ATC heating and A/C system is diagnosed using a scan tool Testing and Inspection.

Prior to replacing an A/C heater control or A/C heater module, check for any Diagnostic Trouble Codes (DTCs) related to the heating and A/C system, and run the calibration procedure to verify that the concern is not an air-door calibration issue HVAC Verification Test.

The individual A/C heater controls located in the switchbank cannot be adjusted or repaired. If an A/C heater control or control indicator lamp is inoperative or damaged, the entire switchbank pod must be replaced Instrument Cluster Switch Pod - Removal.

The individual A/C heater controls located in the U-Connect Touch (TM) screen module cannot be adjusted or repaired. If an A/C heater control or control indicator lamp is inoperative or damaged, the entire U-Connect Touch (TM) screen module must be replaced.